Conventionally, there is known a motor controller that generates a rotating magnetic field by switching an energization pattern of windings of each phase of winding sets by turning on/off a plurality of switching elements of an inverter to rotate a motor.
If the inverter fails to turn ON (ON-state failure) in such a motor controller, the rotation of the motor stops.
On the other hand, in Japanese Patent Application Laid-Open Publication No. 2009-55657, when an ON-state failure of an inverter is detected, a driving of a motor is stopped and it is identified which phase of the inverter has failed to turn ON.
Then, when restarting of the driving is possible, the driving of the motor is resumed by using a switching element of the normal phase.
In Publication No. '657, it is not possible to drive the motor while identifying which phase of the inverter has occurred the ON-state failure.
Further, when the inverter is an H bridge circuit or the like, for example, and there is a plurality of switching elements constituting each phase of the inverter, it cannot be identified which switching element has failed to turn ON.